Method and apparatus for refrigeration



Oct. 10, 1944. I e. w. RUSSELL, JR 2,359,796

METHOD AND APPARATUS FOR REFRIGERATION Filed May 26, 1943 s Sheets-Sheet1 INVEN TOR.

Oct. 10, 1944. w, RUSSELL, JR 2,359,796

METHOD AND APPARATUS FOR REFRIGERATION Filed May 26, 1943 ssneets-s'yieet 2 U INVENTOR. ev tga/ a uoom, 534v BY I G. w. RUSSELL, JR METHOD AND APPARATUS FOR REFRIGERATION 5 Sheets-Sheet 3 Filed May 26,1943 INVENTOR. Q2). amolw, 3%

Qua :30 BY 7 auto (my Wm N Patented Oct. 10,1944

UNITED STATES PATENT or ies Marnop AND APPARATUS FOR REFRIGERATIONGeorge W. Russell, In, Silver Spring, Md., assignor to AmericanInstrument Company, Silver Spring, Md., a partnership Application May2.6, 1943, Serial No. 488,579

(01. 62-915) My invention relates broadly to refrigeration Claims.

and more particularly to a system for selectively controllingrefrigeration temperatures.

One of the objects of my invention is to pro- I vide a method ofselectively controlling refrigeration temperatures at relatively lowtemperature ranges.

Another object of my invention is to provide a method of controllingrefrigeration temperatures by selecting strata or zones of a circulatpared dry ice for the precision control of tem-' peratures bystratification of the gaseous mixture.

Other and further objects of my invention reside in a method andapparatus for selectively controlling temperatures in a dry ice cabinetas invention; Fig. 2 is a transverse section through the dry ice cabinettaken substantially on line 2-2 of Fig. 1; Fig. 3 is a front elevationof the dry ice cabinet illustrated in Figs. 1 and 2 showing thecalibrated temperaturecontrol means adjustable from the exterior of thecabinet; Fig. 4 is a fragmentary plan view of the dry ice compartment ofthe dry ice cabinet taken substan-' tially on line 4-4 of Fig. 1; andFig. 5 is a schematic wiring diagram of one form of control circuitemployed in the refrigeration system of my invention. 4

My invention is directed to a method and apparatus for refrigerationutilizing commercially available blocks of dry ice. A dry icecompartment is arranged adjacent a low temperature or workingcompartment in which the low temperatures are utilized. The dry icecompartment is divided into sections with a container for dry icearranged in a substantially central section or position within thecompartment with. pas

' sages for the circulation of a gaseous mixture both above and belowthe substantially central section. A force fan circulator for thegaseous mixture is located in one section of the dry ice compartment. Atemperature controlled regulator is arranged in the working compartmentand is operative to control a main damper in a "passage or by-passadjacent one section of the dry ice compartment for controlling thecirculation of the gaseous mixture through the dry ice compartment andthrough the by-pass. By circulating the gaseous mixture through the dryice section of the dry ice compartment, temperature conditions over arange of from 5 F. above zero to 110 F. below zero have beensuccessfully developed in the refrigeration system of my invention. Theparticular feature of my invention resides in the arrangement of a:sliding damper adjacent the dry ice section of the dry ice compartment.This sliding damper selects the strata or zone of the gaseous mixtureadjacent the dry ice section of the dry ice compartment which may beselectively circulated through the working compartment. By adjusting theposition of the sliding damper, various stratiflcations or zones of airadjacent the dry ice section of the dry ice compartment may be selectedand the gaseous mixture effectively circulated around the dry icesection and through the working compartment for effective utilization atpredeter mined temperatures. That is to say, my investigations haveshown that for different settings of the sliding damper relative to thedry ice section of thedry ice compartment diiierent strata of coldgaseous mixture are selected and the selected strata when circulatedproduce refrigeration in the working compartment corresponding to thetemperature of the selected strata. The temperature gradient adjacentthe dry ice section of the dry ice compartment is directly dependentupon the displacement-or position of the sliding damper adjacent the dryice section of the dry ice compartment. The sliding damper may be set ina predetermined position for the selection of the strata of thecirculating gaseous mixture adjacent the dry ice compartment. In lieu ofthe presettlng of the sliding damper in a perrefrigeration for theparticular conditions re-* quired. The remote control adjustingmechanism may be suitably calibrated so that the temperatures adaptedfor the particular presetting' of the position of the damper may bereadily determined.

The refrigeration system of my invention provides means for effectivelyutilizing commercially obtainable blocks of dry ice for obtaining lowtemperatures for such industrial purposes as rivet cooling, the testingof aircraft instruments, synthetic rubber testing, the shrinking ofconnecting members for forming tight fits, and for other purposes.

My invention also has application in the quick freezing of foods and inthe preserving of certain vegetables by the freezing process. Inaddition to the industrial applications mentioned, my invention is alsoapplicable in certain domestic refrigeration systems.

My invention will be more fully understood by detailed reference to thedrawings wherein the working compartment of the refrigeration apparatusis represented at 2| and the dry ice compartment is represented at 22.The compartments are formed within a laminated heat insu- 'lation wallstructure designated generally at l5.

The compartments are separated by a main bafile or partition I3containing passages adjacent both the top and bottom. A steel liner I 4is provided for the two compartments adjacent the insulated laminatedWall l5. The exterior of the insulated laminated wall structure I5 iscovered by an external cover material representedat H5. The upperperipheral edge of the insulated wall structure is covered by a layer offelt designated at H. The working compartment 2| is closed by a workingcompartment lid l8 while the dry ice compartment 22 is closed by a dryice compartment lid I9. Thermo-pane Window is provided in the workingcompartment lid l8. This window is formed by a multiple stackarrangement of glass plates spaced by a peripheral separator of sheetmetal and silica gel with the space between the glass plates dehydrated,thus forming a serve as bearings for the adjusting shaft 51. Theadjusting shaft 51 is journalled in the bearings formed by the standards56 and extends through the insulated laminated wall structure I5. A heatinsulating sleeve member 58 forms a' casing surrounding the shaft 51preventing appreciable loss of the low temperatures developed in the dryice compartment 22. The projecting end of shaft 51 carries a gear 59. Anauxiliary gear carried by control shaft 6| journalled adjacent the gear59 meshes with gear 59 and provides an adjusting means therefor. Acasing 52 surrounds the gear system forming a gear housing for thegears. A control knob 63 connects with shaft GI and serves as a manualgrip device for effecting adjustment of the damper 8. The casing 62carries a calibrated dial represented at 64 over which the indicatorsweeps for adjusting the slidable damper 8 to a particular strata orzone of the gaseous mixture within the dry ice compartment 22. Thecalibrated scale 64 enables the damper 8 to be set, adjusted and resetto a selected position.

By shifting the'sliding damper 8 'to different positions, a selectedstrata or layer of cold gaseous mixture may be segregated and circulatedthrough the dry ice compartment over a predetermined temperature range.By shifting sliding damper 8 to a position near the upper extremity ofthe dry ice compartment 22 so that section 24 of the dry ice compartmentbecomes a relatively narrow passage, temperatures in the range of 5 F.above zero may be selected and maintained Whereas upon lowering thesliding damper 8 to a position which substantially exposes the endsection of the dry ice container temperatures in the range of F. belowzero may be selected and maintained. 7

transparent window which prevents the loss of ice indicated generally at26. The support II is formed from a suitable open mesh screen allow ingthe circulation of air between the blocks of dry ice deposited inthesupport The support for the dry'ic'e is insulated at one side byinsulation sheet 2'! and along its bottom throughout a portion of itslength by insulation sheet 28, supplemented by additional sheet 28awhich may be wood or other suitable material. The support or carrier isconstructed from open mesh sheet metal having substantial rigidity whileallowing free circulation of the gaseous mixture around support orcarrier I for the dry ice, I provide a pair of vertically extendingguide. rails 29 which form guides for a vertically adjustable slidingdamper a. The vertically adjustable sliding damper 8 constitutes an endclosure for the carrier for the dry ice shown at H and is' selectivelymovable to different positions adjacent the end of the carrier.

The vertically sliding damper 8 is provided with a pair of rack members55 projecting from one face thereof. The vertically extending guiderails 29 have standards 56 mounted thereon which the dry ice containedtherein. At one end of the 1 The sections 24 and 25 are interconnectedthrough the passage 30 at the' end of, the dry ice compartment andbeyond the sliding damper 3'. A circuitous path around the dry icesection I is completed through passage 3| adjacent. the top of partitionl3, intermediate the working compartment 2| and the dry ice compartment22 and through the confined passage 40 in section 25. A circulating fan32 is located in the confined passage 40 in the section 25 of the dryice compartment 22 and is driven by motor 2 arranged externally of thecabinet structure. The confined passage 40 has an end plate 4| which isapertured at 42 for the entry of circulating fan 32 therethrough. v Theother end of confined passage 40 opens through aperture 43 in partitionI3 into the Working chamber 2|. A drive shaft 33 extending from motor'2drives fan 32 for efiecting forced circulation of air through the dryice compartment according to the path indicated by the circulating linesin Figs. 1 and 2. For the purpose of controlling the circulation. of airaround the dry ice compartment, I arrange a main damper in the section24 of the dry ice compartment. Main damper I is constituted by a valveplate pivotally mounted along one longitudinal edge thereof asrepresented at 34 and arranged to be displaced in position for varyingthe opening for the gaseous medium through passage 3| in partition [3and through section 24' of the dry ice compartment. The main damper I isvaried in position through a connection 35 extending to a solenoidactuator 4 which is in turn controlled by the operation of a relaycircuit controlled by thermostatic regulator 3. The mechanism of therelay circuit and system is con veniently housed incontainer I mountedon one side oi the cabinet.

Fig. shows one form of circuit arrangement for the/control system ofmy'invention. In all instances where the control mechanism is carriedthrough the cabinet structure, I provide heat insulation to preventleakage of heat from the exterior of the cabinet to the interiorthereof. For example, around regulator 3 which extends through theinsulated wall of the cabinet, I provide a heat insulating sleeverepresented at 38 and around the damper actuating mechanism representedat 35 I provide a heat insulation sleeve 31 while around motordrive'shaft 33 there is a heat insulation member 38.

A heating coil 64 is arranged in the confined passage 40 and supportedfrom terminals mounted in end plate 4|. The heating coil 44 may be cutinto and out of the circuit under control of actuator 46 that operatessuitable switch 41 for supplying current through adjustable transformer'48 for energizing heating coils 44; It will'be observed that motor 2drives fan.32 continuously for circulating the gaseous medium throughthe working compartment 2| and the control is brought about by'control.of position 2. The method of controlling temperatures, which comprisessuspending a cold solid in a confined gaseous atmosphere in which thetemperature adjacent the cold solid varies in accordance with theeffective dimensions of the solid, selectively exposing differentdimensional portions of the cold solid to the gaseous atmosphere forselecting stratifications of different temperatures adjacent thecoldsolid, and forcibly circulating a, selected strata of gas aroundsaid cold solid for maintaining a temperature within said confined spacedependent upon the temperature of the selected strata of gas adjacentthecold solid.

3. In a system of refrigeration, a container for receiving a, coldsolid, means for mounting said container within a confined atmosphere, a

' slidable damper arranged adjacent the cold solid of the main damper 1and/or the energization of heating coils 44. Power is supplied to thecabinet through mains indicated at 49 through switch 50. Transformer 5|furnishes reduced potential for control of the button relay circuitindicated at 52 through thermostatic regulator 3 and also the potentialrequired for operation of solenoid actuator 4 that controls main damperl.

7. While I have described my invention in certain preferred embodiments,I desire that it be understood that modifications may be made and thatno limitations upon my invention are intended other than may be imposedby the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is as follows:

1. In a system of refrigeration, the method of controlling temperatureswhich comprises supporting a cold body in a confined passage for agaseous mixture in which the temperature maintained by the cold bodyvaries from a high adjacent the top of the cold .body to a low adjacentthe bottom of the cold body, selecting strata of the gaseous mixture-inthe course of its passage 4 over the cold body and forcibly circulatingthe and shiftable to expose selected portions of the cold solid to theconfined atmosphere, and means for forcibly circulating a gaseousmixture around the selectively exposed portion of the solid.

4. In an apparatus for effecting refrigeration, a cabinet for confininga gaseous mixture, a container for a cold solid, a passage for thegaseous mixture extending adjacent said container, a damper intermediatesaid container and said passage, said damper being shiftable to selectedpositions for selectively exposing selected portions of said solid tothe gaseous mixture in said passage, and means for forcibly cir-Iculating the confined gaseous mixture around the exposed portion ofsaid cold solid for maintaining temperatures proportional totemperatures corresponding to the exposed portions of the cold solid.

5. In an apparatus for effecting refrigeration, a, cab net for confininga gaseous mixture, a container 'for a cold solid, a passage for thegaseous mixture extending adjacent said container, a damper intermediatesaid container and said passage, said damper being shiftable to selectedselected strata of the gaseaus mixture in a confined path around thecold body.

pos tions for selectively exposing'selected portions of said solid tothe gaseous mixture in said. passage, means for forcibly circulating theconfined gaseous mixture around the exposed portion of said cold solidfor maintaining temperatures proportional to temperatures correspondingto the exposed portions of the cold solid, and

means for separately controlling the flow of the gaseous mixtureadjacent the exposed portion of the cold solid. GEORGE W. RUSSELL, JR.

